: : : : : Main Entry: lightning rod
: : : : : Function: noun
: : : : : 1 : a grounded metallic rod set up on a structure (as a building) to protect it from lightning
: : : : : 2 : one that serves to divert attack from another or as a frequent target of criticism

: : : : Your question was clearly worded. The only grammar error is that it should have been "does it mean" rather than "does it means."

: : : It seems to me that the second definition from the dictionary has it both ways. A lightning rod attracts lightning, a dangerous phenomenon, and by doing so protects the house and its inhabitants (because by being grounded it diverts the electric flow directly into the ground). I suspect that the context might reveal that the "lightning rod for controversy" attracts controversy without diverting it safely away. SS

: : Before some fussbudget perfectionist gets his/her undies in a bundle, let us state that we KNOW lightning rods do not "attract" lightning, but instead render it harmless if it should happen to hit the vulnerable house, tree, whatever. That being said, a huge majority of people BELIEVE that lightning rods attract lightning, thus the metaphorical use.

: Well said, and I hope I didn't sound as ignorant as perhaps I ought. I also know that electricity doesn't flow, exactly. I was trying to characterize the situation briefly. I still don't know a good, brief way to explain the actual situation in a way that explains the phrase. SS

Lightning is where earth and sky have opposite charges and the potential becomes so great that it overcomes the insulation of air and leads to a rapid ionisation which conducts a huge quantity of charge. the charge takes the shortest route between earth/sky so 'strikes' the highest point of the land. by raising a metal (conducting) rod above a building that becomes the highest point and so that is where electricity flows.